OLD BRIDGE — Joseph P. Leo spent 45 years in public service as a business administrator, manager and public safety director for many municipalities, including his hometown of Old Bridge.

But what Mr. Leo was really known for was his decade-long leadership of the Middlesex County Republican Organization, trying to make inroads in a county that had one of the state’s most powerful Democratic Party political machines. He also served as GOP chairman in Old Bridge for 10 years.

Mr. Leo, who left the county Republican post in June 2010, died Sunday morning at Bayshore Community Hospital following a lengthy illness. He was 73.

"He was a very longtime friend of mine," said Assemblyman Samuel Thompson (R-Middlesex), who succeeded Mr. Leo to lead the county Republican organization.

"He fought hard to build the party in this county," Thompson said. "He was always leading the charge. He never gave up."

Thompson said Mr. Leo began in politics while still in college at Rutgers University, helping to co-found the Young Americans for Freedom, a conservative political action group that got its start at nationally syndicated columnist William F. Buckley’s home in Connecticut more than 50 years ago.

After obtaining his master’s degree in public administration, Mr. Leo, who was born in Jersey City, moved to Old Bridge, then Madison Township, and began his career in public service.

He served as administrator, manager or public safety director for Holmdel, Marlboro, Jackson Township, Monroe Township, Delran, Brick Township, Middletown, Matawan and two stints in Old Bridge.

Richard Greene, a Republican councilman in Old Bridge, recalled Mr. Leo’s help when he first decided to run for office.

"Joe was instrumental in getting me involved in politics in Old Bridge," Greene said. "If it wasn’t for him, I don’t think I would have done it. He was always available to help anyone who got involved in politics in Middlesex County. He was a wonderful person and a big asset to us."

Robert Brown, who worked with Mr. Leo for more than 40 years in Republican politics, called him "one of the hardest workers I ever met."

"He did a lot of things in his lifetime," Brown, an Edison resident, said. "He was a unique individual."

In addition to his political and public service jobs, Mr. Leo also volunteered his time for the St. Barnabas Burn Foundation and drug- and alcohol-awareness programs, according to statement his family issued.

Mr. Leo is survived by his wife, Kathleen, five sons and five grandchildren.

His wake will be held Thursday from 2 to 4 p.m. and 7 to 9 p.m. at the Michael Hegarty Funeral Home on Route 9 North in Old Bridge. His funeral Mass will be at 10 a.m. Friday at Most Holy Redeemer Roman Catholic Church on Amboy Avenue in Matawan.